Python execute playsound in separate thread

You may not have to worry about using a thread. You can simply call playsound as follows:

def playy():  
    playsound('beep.mp3', block = False)

This will allow the program to keep running without waiting for the sound play to finish.

Use threading library :

from threading import Thread
T = Thread(target=playy) # create thread
T.start() # Launch created thread

As python multi-threading is not really multi-threading (more on this here), I would suggest using a multi-process for it:

from multiprocessing import Process

def playy():
    playsound('beep.mp3')


P = Process(name="playsound",target=playy)
P.start() # Inititialize Process

can be terminated at will with P.terminate()

If you don't want to get confused by threading stuff Nava could be a better option for you. You can just do

from nava import play
play("beep.wav", async_mode=True)

Up until now it supports mp3 only for MacOS (but supports wav for other OSs). You can always convert your mp3 to wav.